High compression for staking tool

ABSTRACT

A staking tool wherein staking dies are compressed by a toggle linkage having unequal arms pinned to each other about a common pivot point, the longer toggle arm being further provided with a cam matingly slidable on a cam follower pivoted in an arcuate motion by a manually actuated handle. The staking dies may be adjusted for selecting variable staking pressure, and a positive stop is provided to prevent undesired excessive staking compression.

United States Patentlll] 3,630,068

Edwin Floyd, Jr.

P.O. Box 2201, Harrisburg, Pa. 17105 [21] Appl. No. 39,692

[22] Filed May 20, 1970 [45] Patented Dec. 28, 1971 [72] Inventor [54] HIGH COMPRESSION FOR STAKING TOOL 410,451; 81/313, 314, 342, 367, 383.5, 341, 375-380, 363; 29/200 H, 203 H, 203 HC, 203 HM, 203 HT, 280, 282

3,393,438 7/1968 Marley et a1 72/451 2,892,368 6/1959 Demler 81/15 3,571,888 3/1971 Di Filippo 29/203 3,322,008 5/1967 Filia 81/313 3,426,355 2/1969 Over 29/203 HT 2,985,047 5/1961 Van Oort 81/341 FOREIGN PATENTS 1,342,312 9/1963 France 81/313 Primary Examiner-Charles W. Lanham Assistant ExaminerMichael J. Keenan Attorneys-William .l. Keating, Ronald D. Grefe, Gerald K. Kita, Frederick W. Raring, Jay L. Seitchik and John P. Vandenburg ABSTRACT: A staking tool wherein staking dies are compressed by a toggle linkage having unequal arms pinned to each other about a common pivot point, the longer toggle arm [56] References Cited b f t d l rd b] eIng ur er provI e M a cam ma mg y s I a e on a cam UNITED STATES PATENTS follower pivoted in an arcuate motion by a manually actuated 3,029,670 4/1962 f at 29/203 H handle. The staking dies may be adjusted for selecting variable 542,035 7/1895 wmevel' 81/363 staking pressure, and a positive stop is provided to prevent un- EPllZ desired excessive staking compression. a o I l 210 I48 I46 I54 I66 I32 I24 22 24 86 X I74 I42 I52 I90 I40 I6 a0 '22 32 26 4 I68 \vfl (ll I damn I I 1 4r, I yw 3 v \V 7] 172 I I 9!\ ,1

Ins-C in 'i' as a 90 I 8 0, I64 fl l2 |4 96 A'L'' 7 4 28 I0 r 150 44 84 g I 06 I2 64 o 210 6 I84 8 l '44 54 408 36 \l -2- I s J C) 46 Q ,'..m= 38 I 9 2I0. 70 69 I 52 2'0 82 56 74 15' '77 7s 62 \66 PATENTED [E628 I97! SHEET 1 OF 2 INVENTOR EDWIN FLOYD, JR. BY M33236) X A 4 w ales 0.068

PATENTED 08228 I971 SHEET 2 OF 2 mm A.

i Q o w: mm mm HIGH COMPRESSION FOR STAKING TOOL FIELD OF THE INVENTION The invention is directed to a hand-operated tool provided with force multiplying linkages in developing high compression forces, particularly for terminating electrical conductors by compression deforming both the conductor and an electrical termination into intimate mechanical and electrical contact.

BACKGROUND OF THE PRIOR ART Heretofore, a hand-operated high compression force staking tool has been provided with a cam-actuated unequal arm toggle link. However, such a tool, exemplified in U.S. Pat. No. 3,492,854, requires a precisely machined and oriented cam follower for producing the desired staking force. A disadvantage in such a tool requires multiple hand strokes to provide the desired cam follower action. A further disadvantage resides in placement of the cam directly at the common pivot point of the toggle arms thereby sacrificing potential force multiplication by the toggle linkage. In a prior art staking tool, typically no provision is made for either adjustable staking pressure or the use of interchangeable staking dies.

SUMMARY OF THE INVENTION The invention is directed to a portable, one-hand manually operated high compression force staking tool which overcomes the disadvantages inherent in a prior art tool. The tool characteristically embodies a force-multiplying toggle linkage with unequal toggle arms, so that a manually applied hand force of approximately 30 pounds applied to the handles of the tool is multiplied to in excess of 3,600 pounds at the staking dies. Such force multiplication is accomplished without requirement for multiple hand strokes and thus enables conductor termination with a single manual stroke applied to the handles of the tool. A further advantage resides in placement of a cam in a location independent from the toggle ann common pivot point. Such cam placement permits additional effective force multiplication by the toggle linkage. The cam cooperates with a follower of fixed geometry and in fixed relationship with respect to a tool handle, thereby minimizing follower alignment. Additional features of the tool include at least one of the handles thereof fixed in relation ship to the main portion of the tool in order to minimize moving parts. Stationary positive stops are provided to prevent application of excessive staking forces. A rack and dog are provided for preventing return motion of the tool handle to prevent incomplete compression applied by the staking tool. The staking dies are adjustable to selectively vary the applied staking forces. The dies are interchangeable with a staking force gauge and with additional dies providing different configurations in the compressed workpiece.

Accordingly, it is an object of the invention to provide a staking tool developing compression forces through a toggle arm linkage having unequal arms.

Another object of the invention is to provide a manually operated staking tool developing high compression staking forces with a single manual hand stroke to effect staking without a requirement for multiple hand strokes.

A further object of the invention is to provide a high compression staking tool with stationary positive stops preventing undesired excessive staking forces.

Still another object of the present invention is to provide a staking tool with a force-multiplying toggle linkage, the actuation of which and the motion of which is controlled by a cam and follower.

Still another object of the present invention is to provide a staking tool having an adjustment feature for selectively varying the staking pressure developed by the tool.

Still another object of the invention is to provide a staking tool allowing use of interchangeable staking dies.

Other objects and many attendant advantages of the invention will become apparent upon perusal of the following detailed description taken in conjunction with the following description of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation of a preferred embodiment of a hand tool according to the invention in a fully closed position, with a cover plate removed and with other parts in section to illustrate details thereof;

FIG. 2 is a fragmentary elevation of a portion of the preferred embodiment illustrated in FIG. 1, showing the tool in a fully opened position; and

FIG. 3 is a fragmentary elevation of a preferred embodiment as shown in FIG. 1 and further illustrating in exploded configuration, staking dies used in the tool according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With more particular reference to the accompanying drawings, FIG. 1 illustrates generally at l a tool according to the invention. The tool is provided with an enlarged C-shaped staking die holder 2 provided with a planar stop portion 4 contiguous with a planar table 6, which table is perpendicular to the stop portion. The portion 4 is provided therethrough with a bore 8 opening in an enlarged recess 10. The table 6 extends between the stop portion 4 and another stop portion 12 generally parallel to the stop portion 4 and terminating in a planar sidewall 14 parallel to the table 6. ln spaced parallel relationship with the sidewall 14 is another planar sidewall 16 extending over a portion of the table 6 as well as the sidewall 14. The table 6, the sidewall I4 and the sidewall I6 are connected by a planar web 18 which additionally forms a backing plate of the tool 1. More particularly, the backing plate l8 extends between the sidewall portions 16 and 14 thereby forming a U-shaped channel defined by the sidewalls 16 and 14 projecting from the planar backing plate 18. Sidewall portion 16 terminates in an end wall 20 with a generally relieved sidewall 22 connecting the sidewall 16 and the end wall 20. The backing plate 18 projects beyond the end wall 20 and is provided with a generally elongated handle portion defined by parallel reverse curved edge margins 26 and 28, connected by a generally arcuate end margin 30. The margins 26 and 30 are provided thereover with a generally resilient covering 32 generally of the same configurations as that of the margins 26 and 30 and affording a manually graspable gripping surface for the tool 1. For example, the covering 32 is provided with apertures one of which is shown at 34, for accepting suitable fasteners, not shown, securing the covering to the portion 24. Accordingly, the covering 32 and the portion 24 together comprise a manually grippable handle which is in fixed relationship with the C-shaped portion 2 of the tool.

The edge margin 28 of the elongated backing plate portion 24 is provided thereon with a projecting planar stop portion 36. Backing plate portion 24 is further provided with a side margin 38 adjacent to the stop portion 36 and extending contiguous with an edge margin portion 40 which, together with the inclined margin 38, defines a flange 42 generally projecting from the C-shaped portion 2. The C-shaped portion 2 is provided, immediately adjacent to the flange 42, with an inclined sidewall 44 extending generally inclined from the sidewall 14 and terminating in an arcuate sidewall portion 46 adjacent to the flange 42. The sidewall 46 is contiguous with a sidewall 48 inclined with respect to the edge margin 40. The sidewall 48 is, in turn, contiguous with a planar sidewall 50 which is provided with a generally arcuate sidewall portion 52 contributing the characteristic C-shaped configuration of the portion tool.

The flange 42 is provided thereon with a projecting pin 54 in adjacent spaced relationship with respect to the sidewall portions 44 and 46. Pivotally attached to the pin 54 is a tapered terminal end portion 56 of a movable handle assembly illustrated generally at 58. The tapered portion 56 is immediately adjacent to a generally elongated portion 60 contiguous with an elongated reverse curved handle portion 62 defined between parallel spaced reverse curved side margins 64 and 66 connected by a generally arcuate end margin 68. A covering 69 similar to the covering 32 is secured by fasteners located in recesses 70, for example. The margin 64 is provided thereon with a projecting planar stop portion 71 adapted to buttingly engage the stop portion 36, for a purpose to be hereinafter explained. Extending between the stop portion 71 and the elongated portion 60 is a projecting tab portion 73 provided to purposely overlie the edge margin portion 38 of the backing plate 18. Overlying the elongated portion 60 of the handle 58 is provided a generally rectangular mounting block 74 secured to the portion 60 by spaced rivets 75. The mounting block 74 is provided with a depending tab 76 in spaced relationship from the pin 54. The tab 76 is provided therethrough with a reduced diameter bore 77. The mounting block 74 is provided with a generally arcuate-shaped projecting portion 78 encompassing therein a slot cam follower, the slot configuration formed by parallel spaced sidewalls 79 connected by arcuate end walls 80 and 81. A coil spring 82 is coiled in surrounding relationship on the pin 54, with the spring 82 overlying the tapered portion 56 of the handle 58. The spring 82 is provided with an elongated leg 83 extending between the pin 54 and the tab 76 of the mounting block 62, the leg 83 registering within the bore 77 of the tab. The spring 82 is additionally provided with a leg portion 84 adapted to engage against the inclined sidewall 44 of the C-shaped tool portion 2. As shown in FIG. 1, the spring legs 83 and 84 are resiliently biased toward each other when the tool is in its closed position as shown. The spring legs 83 and 84 further bias the movable handle 58 toward an opened position as shown in FIG. 2.

With reference to FIG. 1, a first reverse curved elongated toggle arm is indicated at 85 and is defined by elongated parallel spaced reverse curved margins 86 and 88 connected by an arcuate end margin 90. The margins 86, 88, and 90 may be of the same general configurations as the margins 26, 30, and 28 respectively, of the fixed tool handle 24. In such a construction, the toggle arm 85 may be configured to be disposed entirely within the confines of the tool handle portion 24. in a more specific description of the toggle arm 85, it is provided with an aperture 92 adjacent to the end margin 90 and is received pivotally over a cylindrical pin 94 secured to the bandle portion 24. The toggle arm reverse curved portion 85 terminates generally in an elbow portion 96 connected to a contiguously extending offset leg 98 contiguous with the toggle arm 85. The end portion of the leg 98 opposite from the elbow portion 96 carries thereon a cylindrical pin 102 over which is rotatably mounted a generally cylindrical cam 100, the outer cylindrical dimensions of which extend between the spaced parallel sidewalls 79 of the slot configured cam follower. The reverse curved toggle link 85 is further provided with a laterally extending tab 104 in adjacent spaced relationship to the elbow portion 96 of the reverse curved toggle arm. The tab portion 104 is provided thereon with a projecting pin 106 having rotatably mounted thereover a dog 108 having a projecting nose portion 110 and carrying a projecting pin 112. A coil spring 114 has a hooked end portion 116 secured over the pin 112 and another end portion 118 secured over a pin 120 projecting from and secured to the reversed curved toggle portion 85.

The elbow portion 96 of the reverse curved toggle ami is provided generally centrally thereof with a cylindrical pivot pin 122. A relatively shorter toggle arm elongated portion 124 is provided at one end of said portion 24 with an laterally offset enlarged end portion 126. The terminal end of the offset portion 126 is provided thereon with a plurality of serrations 128 adapted for engaging the nose portion 1 of the dog 108, in a manner to be hereinafter described. Generally at the junction of the elongated portion 124 and the offset portion 126 is provided a circular aperture 130 adapted to be pivotally received over the pin 122, thereby pivotally connecting the shorter toggle arm 124 to the relatively longer, reverse curved toggle arm 84 at a common pivot point supplied by the pivot pin 122. A rounded terminal end 132 of the shorter toggle arm elongated portion 124 is provided with an aperture 134 therein pivotally receiving therein a pivot pin 136. The pin is secured to and projects from a flange 138 which may be of any desired configuration, such as arcuate as shown. The flange 138 projects from an end wall 140 of a ram 142 slidably received in the channel provided by the backing plate 18 and the sidewalls 14 and 16. More particularly, ram 142 is provided with a planar sliding bearing surface 144 slidably received and in abutting relationship with the sidewall 14. The ram 142 is further provided with a planar bearing surface 146 in opposed relationship with respect to the surface 144 and received in sliding abutting relationship on the sidewall 16. The ram 142 is provided with an end wall 148 connecting the bearing sidewalls 144 and 146 and provided generally centrally thereof with a cylindrical recess 150 which communicates and opens into an enlarged cylindrical recess portion 152 giving a generally T-shaped configuration to the recess when viewed at its cross section thereof. The end wall 146 is provided with an internally threaded reduced diameter cylindricaL recess 154 extending in spaced relationship with respect to the cylindrical portion 152 of the recess 150. The recess 154 communicates with the longitudinal axis of the enlarged cylindrical portion 152 by an aperture containing a ball latch 162 therein, which ball latch is adapted to engage a cylindrical, generally T-shaped head 164 of an adjusting screw, the head of which is received rotatably within the recesses 150 and 152. The threaded recess 154 receives a headless setscrew 166 therein, which setscrew is threadably adjusted within the recess to engage the ball latch 162 urging it into engagement against the screwhead 164 which may be slightly recessed as shown in the Figure to accommodate the ball latch. The screwhead 164 is further provided with a cylindrical threaded body portion 168 having a groove 170 in an end portion thereof. The threaded screw portion 168 is received in an internally threaded cylindrical recess 172 provided in an end wall 174 of a ramhead 176. The threaded recess 172 is axially aligned with a reduced diameter bore 178 provided in an end wall 180 operating as a staking die-receiving bearing surface. The end wall 180 is defined between a planar sidewall bearing surface 182 and 184. In practice, the bearing surface 182 slidably abuts against the sidewall 16 of the tool 1, and the sidewall 184 is defined on a laterally extending leg portion 186 and slidably abuts the table 6 of the tool. The leg portion 186 protrudes from a planar sidewall bearing surface 188 which slidingly abuts against the sidewall 14 of the tool 1 when the tool handles are in the fully opened position as shown in FIG. 2. In practice the recess 178 is in alignment with the recesses 8 and 10 provided in the C-shaped portion 2 of the tool 1. The sidewall 16 of the tool is provided with a lateral opening 190 communicating with the ram internally threaded recess 154. A recess 192 defines an end wall for communicating with the sidewall 16 and provides access to a threaded recess 194 in the ramhead 176, which threaded recess communicates laterally with the recess 178.

With reference to H6. 3, a first staking die 196 is shown with a female die portion 198, a planar bearing surface 200 and a projecting pin 202 adapted to be matingly received in the recess 178 of the ramhead 176. A headless setscrew 204 is then threadably received in the threaded recess 194 to engage the pin 202 and retain the die 196 in abutting relationship against the bearing surface wall 180. When thus received, the die bearing surface 200 will slidably abut against the table 6 of the tool 1. In similar fashion, a male staking die portion 206 is provided with a planar bearing surface 208 and a pin 210 adapted to be received in the recess 8 of the tool 1. With the male die member 2 of 6 thus located, the bearing surface 208 thereof is slidably abutted against the table 6 of the tool 1. The die portions 196 and 206 are removable from the tool 1 and thus may be interchanged with other die portions, not shown, enabling use of different die configurations and for commenting different size workpieces, such as varying terminals and electrical conductor sizes to be terminated by operation of the tool.

With reference to FIGS. 1 and 3, operation of the tool will be now described in detail. As shown in FIG. 2, the handle portion 62 is in its fully open position with the spring 83 biasing the handle to remain in such position. More particularly, the spring leg 84 abutting against the sidewall 44 and the spring leg 83 engaged in the bore 77 of the tab 76 are preloaded with a tendency to separate and thus pivot the handle 62 about the pin 54. With the die portions 206 and 198 in place on the tool as described, the handle 62 is pivoted toward a closed position, as illustrated in FIG. 1, against the resilient action of the preloaded spring legs 83 and 84. Such pivotal motion forces the cam roller 100 to traverse along the slot sidewalls 79, with the roller changing from its position shown in FIG. 2 to a position shown in FIG. 1. Such action of the cooperating cam roller and cam follower slot pivots the reverse curved toggle arm 85 about the pin 94 located in the fixed handle 24. The pivot pin 122, common to both the elbow portion 96 and the relatively shorter toggle arm 124, is thereby urged to pivot in an arcuate path, the pivotal center of which path is located at the pin 94. Such pivotal motion of the pin 122 causes a corresponding pivotal motion of the shorter toggle arm 124 about the pin 122. Accordingly, the serrations 128 on the end portion 126 of the shorter toggle arm is caused to traverse the nose 110 of the dog 108. The coil spring 114 urges the dog to pivot counterclockwise about its pivot pin 106 to ensure that the nose 110 is maintained in engagement upon the serrations 128 as they pass. Should pivotal motion of the handle 62 inadvertently be terminated before attaining its fully closed position illustrated in FIG. 1, the dog nose 110 will wedgingly engage in one of the serrations 128 preventing return pivotal motion of the handle 62 created by the resilient action of the spring legs 83 and 84. Accordingly, the dog 108 locks the handle 62 from return pivotal motion until obtaining its fully closed position as shown in FIG. 1.

As noted in the FIGS, the shorter toggle arm 124 is pivotally connected to the pin 136. Translation of the pin 136 is constrained by the ram 142 to sliding motion parallel to the sidewalls l4 and 16. Accordingly, pivotal motion of the handle 62 to a closed position, not only pivots the shorter toggle arm 124, but urges the toggle arms progressively to aligned positions. More particularly, as the common pivot pin 122 is progressively pivoted into alignment with the toggle arm pivot pins, 94 and 136, the familiar toggle linkage operation is readily identified, multiplying the forces utilized in pivoting the common pivot pin 122 into a force transmitted from the pivot pin 94 to the pin 136. Since the pin 136 is constrained from displacement parallel to the sidewalls 14 and 16, such force multiplication is transmitted through the ram 142 and the ramhead 176 to the die portion 196, forcing it into compression with the male die portion 206. As shown in the drawing, the effective length of the toggle arm 85 between the pivot pins 94 and 122 is approximately four times the effective length of the toggle arm 124 between the pins 136 and 122.

With the handle 62 pivoted to a fully closed position in FIG. 1, the stop 71 thereof will abut against the stop 36 provided on the handle portion 28, indicating to the operator of the tool that completed pivotal motion of the toggle 62 is accomplished. With the handle in its fully closed position, the serrations 128 will completely pass the dog nose 110 as shown in FIG. 1, and the ramhead 176 will be in its fully extended position protruding from the sidewalls 14 and 16. Return pivotal motion of the handle 62 is readily accomplished by the action of the resilient spring legs 83 and 84 as described. The cam will return along the cam follower slot to its position shown in FIG. 2 and the toggle arms 85 and 124 will return to the position shown in FIG. 2. Such pivotal motion of the toggle arms will retract the ramhead 176 to its position shown in FIG. 2. The action of the dog 108 and the serrations 128 operate as a double-acting ratchet, a feature known in the prior art as certigrip, manufactured by AMP Incorporated, Harrisburg, Pa.

The particular toggle mechanism described multiplies a force of 35 pounds, required to pivot the handle 62 to a fully closed position, to a force of 3,600 pounds upon translation of the ramhead 176, with approximately I of misalignment of the pivot pin 122 from a straight line intercepting the pivot pin 94 and 136. As shown in FIG. 1, the pivot pin 122 is purposely provided with such misalignment with the handle 62 in its fully closed position to prevent locking of the toggle mechanism. Additional force multiplication is provided by the leg portion 98 of the longer toggle arm 85. More particularly, the leg 98 locates the cam roller 100 in a position remote from the common pivot pin 122. Further, pivotal motion of the handle 62 applies pivotal forces to the toggle arm at an effective lever length governed by the spacing between the pivot pin 94 and the cam roller pin 102. Such effective lever length is longer than that provided by the spacing between the pins 94 and the common pivot pin 122. Thus, the force applied to the cam roller is transmitted, by pivotal motion of the toggle arm 84, to an even greater force applied at the pin 122, which force is utilized to actuate the toggle linkage and provide the staking pressure upon translation of the ram 176.

A further feature of the invention will be described with reference of FIG. 1 of the drawings. In the Figure, the headless screw 166 may be threadably disengaged from the ball latch 162, access to the screw being provided by the opening 190 in the sidewall 116. The ball 162 will then be disengaged from the T-shaped screwhead 164. A suitable tool, not shown, may be inserted in the opening 178 of the ramhead 176 to engage in the groove 170 of the screw 168. By rotation of the screw by the tool, the spacing of the ramhead 176 from the ram 142 may be selectively preadjusted so that, in subsequent use of the tool, any desired staking pressure between the staking dies 206 and 196 may be selected. Alternatively, the tool may be inserted through the aligned recesses 10 and 8, as well as through the recess 178, to effect rotation of the screw. When sufficient adjustment is accomplished, the screw 166 is again tightened to engage the ball 162 which, in turn, engages against the screwhead 164 to prevent any additional undesired turning of the screw.

As an additional feature of the invention, the cam follower slot is of easily machined configuration requiring only parallel spaced sidewalls 79 enabling simplified manufacture thereof. The slot follower also is of stationary configuration with respect to the handle 62 preventing misalignment thereof during use and minimizing the number of moving parts. To further eliminate the number of moving parts, the tool handle 24 remains in fixed relationship to the C-shaped portion 2 of the tool. Sufi'rcient force multiplication is provided with only a single hand stroke to effect a desired high compression for staking without requiring a multiple hand stroke. The provision of a toggle linkage having a four-to-one effective unequal arm length permits a high degree of force multiplication in a compact hand tool. Additionally, the provision of a lever arm afforded by the leg 98 permits additional force multiplication utilized in operating the linkage as described. The stops 36 and 71 are of stationary fixed geometry, minimizing the number of moving parts and preventing any misadjustment thereof during prolonged tool use. The staking die portions are interchangeable with alternate portions for a variety of reasons, such as accommodating different size workpieces, selecting different die configurations and selection of different die mating pressures.

Other modifications and embodiments of the invention are probable, for example, the provision of a cover plate which may be suitably provided on the tool to cover the moving parts thereof, which cover plate may be suitably attached by fasteners located in the apertures 208 as shown.

What is claimed is:

l. A staking tool comprising: receiving means for receiving a pair of staking die portions, a manually graspable handle portion fixedly secured to said die-receiving means, a manually graspable movable handle portion pivotally mounted on said fixed handle and movable from an open position to a closed position, a cam follower fixedly secured on said movable handle portion, a toggle linkage including a first arm pivotally mounted to said fixed handle portion and a second arm pivotally mounted to said first arm at a common pivot point, a ram constrained for rectilinear reciprocation, a ramhead provided on aid ram and mounted for rectilinear reciprocation upon said die-receiving means, said second arm pivotally connected to said ram, a cam provided on said toggle link and matingly engaging said cam follower, a first staking die portion fixedly mounted on said die-receiving means, and a second die portion engaged by said ramhead and mounted for rectilinear reciprocation on said die-receiving means, whereby pivotal motion of said movable handle portion from an open to a closed position causes said cam to traverse over relative spacing therebetween.

4. The structure as recited in claim 1, and further including: means provided on said movable handle portion to bias the same to an open position, the pivotal motion of said movable handle from an open position to a closed position being accomplished against such biasing action.

5. The structure as recited in claim 1, and further including: stationary, fixed geometry stop means provided on said movable handle portion and said fixed handle portion and cooperating to positively limit pivotal motion of the movable handle portion beyond a desired closed position.

6. The structure as recited in claim 1, wherein said first toggle arm and said second toggle arm have an effective length ratio of four to one.

7. The structure as recited in claim 1, wherein said first toggle arm includes a leg portion extending from said common pivot point, and said cam is mounted on an end of said leg portion remote from said common pivot point.

8. The structure as recited in claim I, wherein said follower comprises a mounting block provided with a slot therein, and said cam is a roller adapted for translation within said slot upon pivotal motion of said movable handle portion. 

1. A staking tool comprising: receiving means for receiving a pair of staking die portions, a manually graspable handle portion fixedly secured to said die-receiving means, a manually graspable movable handle portion pivotally mounted on said fixed handle and movable from an open position to a closed position, a cam follower fixedly secured on said movable handle portion, a toggle linkage including a first arm pivotally mounted to said fixed handle portion and a second arm pivotally mounted to said first arm at a common pivot point, a ram constrained for rectilinear reciprocation, a ramhead provided on said ram and mounted for rectilinear reciprocation upon said die-receiving means, said second arm pivotally connected to said ram, a cam provided on said toggle link and matingly engaging said cam follower, a first staking die portion fixedly mounted on said die-receiving means, and a second die portion engaged by said ramhead and mounted for rectilinear reciprocation on said die-receiving means, whereby pivotal motion of said movable handle portion from an open to a closed position causes said cam to traverse over said cam follower and reciprocate said ram and said ramhead in order to translate said movable die portion into mating engagement with said fixed die portion and provide staking compression therebetween.
 2. The structure as recited in claim 1 wherein said fixed die portion and said movable die portion are removably mounted on said die-receivinG means.
 3. The structure as recited in claim 1 and further including: means connecting said ram and said ramhead for adjusting the relative spacing therebetween.
 4. The structure as recited in claim 1, and further including: means provided on said movable handle portion to bias the same to an open position, the pivotal motion of said movable handle from an open position to a closed position being accomplished against such biasing action.
 5. The structure as recited in claim 1, and further including: stationary, fixed geometry stop means provided on said movable handle portion and said fixed handle portion and cooperating to positively limit pivotal motion of the movable handle portion beyond a desired closed position.
 6. The structure as recited in claim 1, wherein said first toggle arm and said second toggle arm have an effective length ratio of four to one.
 7. The structure as recited in claim 1, wherein said first toggle arm includes a leg portion extending from said common pivot point, and said cam is mounted on an end of said leg portion remote from said common pivot point.
 8. The structure as recited in claim 1, wherein said follower comprises a mounting block provided with a slot therein, and said cam is a roller adapted for translation within said slot upon pivotal motion of said movable handle portion. 